2026 ICD-10-CM Diagnosis Code S01.502AUnspecified open wound of oral cavity, initial encounter
S01.502A is a billable ICD-10-CM diagnosis code for unspecified open wound of oral cavity, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 157 through 159, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Any dental condition including traumatic injury; and Open wounds of head and neck, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Avulsion of mandibular attached gingiva
- Avulsion of mandibular vestibule
- Avulsion of maxillary vestibule
- Avulsion of tongue
- Fracture of palatal process
- Fracture of palate, open
- Healing wound of periodontal tissue following dental trauma
- Multiple open mouth wounds
- Multiple open wounds of head
- Open wound in mouth
- Open wound of buccal mucosa
- Open wound of gum
- Open wound of mouth floor
- Open wound of palate
- Open wound of tongue
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Open wound of head (S01). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Mouth Disorders
Your mouth is one of the most important parts of your body. It has many different functions. It allows you to:
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Convert S01.502A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S01.502AOverview
Is S01.502A (Unspecified open wound of oral cavity) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified open wound of oral cavity, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S01.502A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for unspecified open wound of oral cavity, such as an emergency visit or first evaluation.
What MS-DRG does S01.502A group to?
When unspecified open wound of oral cavity, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 157, 158, 159, 963, 964, 965, with relative weights from 0.7085 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S01.502A?
Under the General Equivalence Mappings, unspecified open wound of oral cavity, initial encounter converts to ICD-9-CM 873.60 (open wound of mouth NOS). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
